Review: Ferdinand Berthoud Chronomètre FB1R.6-1

Here, we review the Ferdinand Berthoud Chronomètre FB1R.6-1, yet another interesting iteration on the base FB1 movement. The same base movement powers the entire series. But the ingenious methods employed to harness this base movement is absolutely interesting. Apart from the case material changes, each of the iterations also carry interesting changes to the base movement. The FB1.4 saw the introduction of sapphire bridges in a titanium case in late 2017. And the latest iteration was launched in SIHH 2018 in the form of the FB1R.6-1 featuring a large sweep seconds hand in a regulator style dial showing the hours in digital format.

The F. Berthoud FB1R.6-1’s dial is strongly influenced by an original drawing published by Berthoud in the Traité des Horloges Marines (1773)

In the review of the F. Berthoud FB1.4, we spoke about how Karl-Fredrich Schuefele (KFS) went to great lengths to the re-interprete the works of Ferdinand Berthoud. KFS and his team certainly have not chosen the easy way out by copying the body of work already done by Berthoud, but instead, they chose to study the works, and re-imagine it as if Berthoud had access to the modern materials and technology existing today. The result is a series of watches which draw inspiration and direction from the Berthoud watches, clocks and drawings, but with a completely modern feel. The base movement, FB1 was developed with a suspended reverse fusée and chain system to power a large tourbillon, and a unique conical power reserve. And yet, each iteration carries with it some unique innovation. From the firstFB1 to FB1.3, the main difference is the case material being offered, from white gold to rose gold and platinum (a specially developed platinum alloy) respectively. FB1.4 showed additional technical innovation being introduced. This being the use of sapphire glass bridges. Also accompanying the FB1.4 is the closure of the ports at the side of the case, now crafted in titanium.

And this leads us to FB1R.6-1, which carries a different design dialect, so to speak, as it is now a regulator. But not in the traditional sense. In a classical regulator layout, the minute hand occupies the largest real estate and the seconds and hours are subdials. The FB1R.6-1 features a regulator in the design first seen in a drawing published by F. Berthoud in Traité des Horloges Marines (1773). The dial layout is unusual, to say the least, leaving a large negative space for one to contemplate. And to focus on the elements which are presented on the dial. But also, true to the original drawing, a large centrally mounted seconds hand takes pride of place, and the hour display is on a moving disc as a subdial and displayed digitally. Prominently displayed is the patented power reserve mechanism. A rather bold design aesthetic, and perhaps a gamble. But one which we judge to have been taken with careful consideration and which we think is largely successful.

Ferdinand Berthoud FB1R.6-1

The naming convention is certainly a mouthful, and perhaps a more logical nomenclature needs to be developed. The series started as the FB1, and without having an FB1.1, jumps to 1.2 in white gold and progress logically to 1.3 in a specially developed platinum. The 1.4 followed in a titanium case. Then we arrive at the FB1R.6-1 in stainless steel. We suppose the R in the FB1R.6-1 denotes the regulator status, but remain a bit perplexed that FB1.5 seemed to have disappeared. Further, the -1 at the end of the model name seem to imply there will be other versions, but F. Berthoud remains mum.

While the naming convention may be a bit confusing, what is not confusing is the excellent aesthetics of the watch, albeit a bit unconventional. This is clear as one gazes on the dial. We find it rather appealing. The design is clean, and suggests an honest approach to watchmaking.

The Case, Dial and Hands

As mentioned, the dial layout is unusual. At the risk of repeating, the dial is a regulator style format laid out like the drawing that Berthoud published in 1773. The main display is the huge, centrally mounted seconds hand sweeping over the entire dial.

Design sketch of the FB1R.6-1.

Two subdials are used to display the hours and minutes. The hours are shown through an aperture on the dial, with an arrow indicating the hour which is on a rotating disc. The minutes are shown in a more conventional subdial at 12 o’clock. The center of the minute subdial is also opened up to reveal some of the movement wheels.

Time indication: 10:55:13.

At 10 o’clock, the dial displays the patented power reserve. Visible via an aperture on the dial is the entire mechanism. Showing the spring which traces the outline on the suspended cone, to show the power reserve.

The power reserve indicator, showing the spring, and the tracing arm.

The power reserve indication system is quite sophisticated, and Berthoud has filed a patent for it.

The FB1R.6-1 returns to the open portholes at the side to allow a peek into the fusée chain system.

The fusée chain system visible through the porthole in the case side.

The case design is rather complex, but follows largely from the design first established in the FB1. The diameter remains at 44mm, with a thickness of 14mm. And it is composed of a steel cylinder housing the movement.

The stainless steel used is a special steel which Berthoud described as one whose molecular structure has been reinforced by a thermo-chemical process involving vapout-phase carbon. A hardness value of 1200 Vickers is quoted, which makes it extremely robust, and corrosion resistant.

The special treated steel used in the FB1R.6-1 on the right, shown to be resistant to scratching with a nail. The left ingot is regular stainless steel, which shows the scratches readily.

Interestingly, the dial does not feature a cutout for the tourbillon, unlike the earlier iterations which proudly show the magnificent tourbillon.

The Movement

The movement remains based on the FB-T.FC, now with a .R tagged to it to denote the regulator status. From the case back, the movement looks similar to its other siblings. The movement finishing is still top grade, with all the finissage of haute horlogerie taken to the highest form of the craft. The movement plates are rhodium plated maillechort.

The power reserve indicator

Visible through a cut-out in the half-bridge on the case-back side, a truncated cone (indicated by the arrow in the photograph below) moves up and down along an arbor connected to the barrel. This suspended cone is topped by a feeler spindle in the form of a mobile arm tipped with a watch jewel. The latter’s position on the cone reflects the barrel’s state of wind. The feeler spindle in turn transmits the quantity of energy accumulated by the mainspring to a set of finely chamfered and rhodium-plated flat levers visible through a cut-out in the regulator plate on the dial side. Its role is to amplify the displacement of the power-reserve hand. A spiral spring placed at the far end of its travel exercises a force on the base of the power-reserve hand. This spring serves to compensate for the play between the various components of this mechanism and to display the power reserve with peerless precision.

The yellow arrow shows the cone of the power reserve indicator.

The geometry of the spring is rather complex as it is needs to guarantee concentric deployment of the coils in all states of winding and unwinding. Any distortion in the geometry will be detrimental to the smooth running of the power reserve indication system.

The Tourbillon

The tourbillon and its single arm cock is splendidly finished, and is a case in point. The arm features an attachment plate which is a stylised arrow head. Te bridge is beautifully hand-polished and chamfered. The 67 components of the tourbillon are assembled within the titanium carriage with the signature large size of 15.66mm diameter. Poising duties of the escapement is via two 18k gold inertia blocks and the movement is COSC certified.

Though the tourbillon makes one revolution per minute, it does not carry a seconds hand, as the FB1R.6-1 is one of the rare tourbillons with a central sweep seconds hand.

Maintaining power and the winding system

The fusée and chain system is equipped with a Maltese Cross stopwork. This device is used to limit the winding of the mainspring (it blocks the mainspring after 6 turns), so that only the most linear part of the spring discharge is used. It also acts as a buffer when the barrel is fully wound. The mainspring torque exerts 3 kg force when fully wound.

The FB1R.6-1 is equipped with a crown dynamometric device to avoid damage caused by excessive winding.

As is visible on the photograph below, on tip of the barrel is a maintaining power mechanism. This system is needed for fusée systems as the barrel drum turn in one direction during unwinding to power the movement train, but the other when it is being wound. Without a maintaining power mechanism, the movement will stop when the watch is being wound. To prevent this, the FB-T.FC.R calibre is equipped with a differential gear maintaining power system. This mechanism is an original concept (unlike the one used in the Lange Tourbillon Pour le Mérite, for example) and for which patent has also been filed.

The fusee and chain system. Visible is the Malteze Cross and maintaining power system.

The winding mechanism is fitted with a pinion featuring cone-shaped toothing. Coupled with a large-diameter knurled crown, it enables smooth movement winding. The winding feel through the crown is exceptionally smooth and fine.

The Competitive Landscape

Regulator watches fitted with a tourbillon and a fusée chain system are hard to come by. If we add a power reserve indicator, then perhaps the FB1R.6-1 is the sole occupant in the landscape.

Introduced in 2010 in a platinum version (limited edition of 100 pieces which is sold out), and in pink gold (US$ 193,000 limited production), a white gold Boutique only edition (€ 171,900 limited production) is added later. The Lange regulator dial is more conventional, in the sense that it has the minutes displayed centrally, with subdials for the hours and seconds, as opposed to the FB1R.6-1’s sweep seconds hand, and subdial for the minutes and a rotating digital display of the hours. Both feature a tourbillon with a fusée chain constant force system, although the Lange implements the standard fusée, and not an inverted one used in the Berthoud. The Lange also lacks a power reserve indicator, but perhaps more than make up for it by the innovative a stop seconds mechanism by hacking the tourbillon. Another aesthetically interesting feature on the Lange is the implementation of the switching subdial to allow a full view of the tourbillon through a cutout, and yet allows time to be read when the hour hand is over the tourbillon dial cutout. Please see our review for full details.

The Akrivia Regulator Tourbillon (CHF 125,000 before taxes in a stainless steel case)is also a regulator tourbillon, But like the Lange, it also follows the conventional large central minute hand and subdials for the hours and seconds. The watch does not feature a power reserve indicator or a fusée chain system. Rebellon also has a tourbillon regulator, but also no fusée chain.

Parting Thoughts

While we found the aesthetics of the F.Berthoud Chronometrie FB1R.6-1 to be very appealing, we get feedback from readers in our little informal poll at the Chief Editor’s IG account (@peterdeployant) that the design is not for everybody. We get it. We also get Berthoud’s idea of the layout – the negative space playing well to the central seconds hand, and the digital disc for hours, the subdial for the minutes, and an aperture to show the workings of the power reserve indicator. The watch from the back is equally compelling. The movement is gorgeous, and the huge tourbillon is mesmerising to behold. The fusée and chain and partially visible suspended cone of the power reserve system offers a treat to the eyes.

We find the case size of 44mm and 14mm high to be quite comfortable. And the large crown to be easy to work with when winding the watch or to set the time. At CHF 230’000.00 or US$ 241,000.00, the FB1R.6-1 is understandably high for a watch with this level of quality in design and execution. But for those looking for a historically inspired watch, well thought out design, magnificently executed, we think the asking price is perhaps fitting.